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From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date:   Thu, 6 Dec 2018 19:01:38 +0100
Message-ID: <CAKv+Gu97MU5kU878gF=KBLxQ5GjZatAbJ-LVdKv-QMgdPh3kZQ@mail.gmail.com>
Subject: Re: [RESEND PATCH] efi: let kmemleak ignore false positives
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     Qian Cai <cai@gmx.us>, Andrew Morton <akpm@linux-foundation.org>,
        Marc Zyngier <marc.zyngier@arm.com>,
        linux-efi <linux-efi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Thu, 6 Dec 2018 at 19:00, Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Thu, Dec 06, 2018 at 11:16:33AM -0500, Qian Cai wrote:
> > unreferenced object 0xffff8096c1acf580 (size 128):
> >   comm "swapper/63", pid 0, jiffies 4294937418 (age 1201.230s)
> >   hex dump (first 32 bytes):
> >     80 87 b5 c1 96 00 00 00 00 00 cc c2 16 00 00 00  ................
> >     00 00 01 00 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b  ........kkkkkkkk
> >   backtrace:
> >     [<000000001d2549ba>] kmem_cache_alloc_trace+0x430/0x500
> >     [<0000000093a6dfab>] efi_mem_reserve_persistent+0x50/0xf8
> >     [<000000000a730828>] its_cpu_init_lpis+0x394/0x4b8
> >     [<00000000edf04e07>] its_cpu_init+0x104/0x150
> >     [<000000004d0342c5>] gic_starting_cpu+0x34/0x40
> >     [<000000005d9da772>] cpuhp_invoke_callback+0x228/0x1d68
> >     [<0000000061eace9b>] notify_cpu_starting+0xc0/0x118
> >     [<0000000048bc2dc5>] secondary_start_kernel+0x23c/0x3b0
> >     [<0000000015137d6a>] 0xffffffffffffffff
> >
> > efi_mem_reserve_persistent+0x50/0xf8:
> > kmalloc at include/linux/slab.h:546
> > (inlined by) efi_mem_reserve_persistent at drivers/firmware/efi/efi.c:979
> >
> > This line,
> >
> > rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);
> >
> > Kmemleak has a known limitation that can only track pointers in the kernel
> > virtual space. Hence, it will report false positives due to "rsv" will only
> > reference to other physical addresses,
> >
> > rsv->next = efi_memreserve_root->next;
> > efi_memreserve_root->next = __pa(rsv);
> >
> > Signed-off-by: Qian Cai <cai@gmx.us>
>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>\

I don't see the patch and I wasn't cc'ed